Device for controlling the flow of refrigerant in alpha refrigerating apparatus



Nov. 22, 1932. E. H. THREADGILL 1,888,517

DEVICES FOR CONTROLLING THE FLOW 0F REFRIGERANT IN A REFRIGERATING APPARATUS Filed March 3, 1931 I zy- INVENTOR WITNESS Lib. 771read ill 7 151 M BY 9 ATTORNEY Patented Nov, 22, 1932 UNITED STATES PATENT OFFICE EUGENE H. THREADGILL, OF RALEIGH, NORTH CAROLINA DEVICE FOR CONTROLLING THE FLOW OF REFBIGER-ANT IN- A REFRIGERATING APPARATUS Application filed March 3, 1931. Serial No. 515,908.

This invention relates to a device for controlling the flow of refrigerant in a refrlgerating apparatus.

An object of the invention is the provision of a device for controlling the flow of a refrigerant through the increase of temperature of the expanding refrigerant which affects a thermostatic bulb, the control being also affected by the increase or decrease of the pressure within a pipe which is in communication with the expansion coil of a refrigerator.

A further object of the invention is the provision of a device for controlling the flow 7 of a refrigerant through the expansion coils of a refrigerating apparatus from the outlet side of the usual compressor, a valve being included in the control which is moved to a closed or open position by variations in pressures on a liquid contained in an expansible I member connected to the valve, a thermostat ic bulb containing a medium responsive to temperature changes being in communication with a chamber embracing the expansible member, the medium exerting a pressure on the expansible member to move the valve to open position when the pressure exerted by the medium in the bulb is suificient to overcome the back pressure of the refrigerating medium in the expansion coils.

A still further object of the invention is the provision of a device which is associated with a refrigerating machine and may be located in any part of the system and will '35 work effectually for controlling the flow of a refrigerant to the expansion coils of a refrigerating apparatus, the device being so constructed that there is no danger at any time of any of the fluids used in the device becoming frozen.

This invention will be best understood from a consideration of the following detailed description, in view of the accompanying drawing forming a part of the specifica- 45 tion; nevertheless, it is to be understood that the invention is not confined to the disclosure, being susceptible of such changes and modifications which shall define'no material departure from the salient features of the in 50 vention as expressed in the appended claims.

In the drawing:

' ically a refrigerating apparatus showing my controlling device applied thereto,

Figure 2 is a vertical section of the controlling device, and

Figure 3 is a horizontal section taken along the line 33 of Figure 2.

Referring 'more particularly to Figure 1, it will be seen that a compressor 10 driven by a motor 11 is adapted to receive the expanded refrigerant from a pipe 12. The compressed refrigerant is conducted from the compressor by means of a pipe 13 which leads to my control device, generally designated by the numeral 14. An outlet pipe 15 connects the controlling device 14 with one end of the exy pansion coils 16. The other end of the expansion coil is connected with the pipe 12.

The controlling device 14 consists of a bowl having a chamber 21/therein and having its upper end open. A cap 22 .is threaded, at 23, into the upper end of the bowl 20 for closing the chamber 21.

The lower end of the bowl is provided with a nipple 24 having a central threaded passage 25 to receive a plug 26 having a manipulating head 27. A look nut 28 is threaded onto the plug 26 and engages the outer end of the nipple 24 for retaining the plug in a predetermined position.

The outer surface of the bowl 20 is provided with fins 29 extending vertically and radiating from the outer wall. These fins are for the purpose of aiding in the dissipation of heat from the bowl 20.

A cap 22 is provided with an extension 3 having-a chamber 31 which is in communication with the threaded end 32 of the inlet pipe 13. The chamber 31 may be termed the high pressure chamber due to the fact that the refrigerant passing through the chamber from the pipe 13 is under pressure from the compressor 10. [I

The extension has a low pressure chamber 33 and a passage 34 which connects the chamber 31 with the interior 35 of an expansible member 36 places the low pressure chamber 33 in communication with the chamber 31. The pipe 15 has a portion 37 threaded into a passage 38 in the extension 30 so that the chamber 33 will be in communication with the pipe 15.

A valve 40 is adapted to engage a seat 41 at the bottom of the chamber 31 and is connected to a stem 42 which extends downwardly through the passage 34 and is connected at 43 with the bottom 44 of the expansible member 36. p

The expansible member is located within the chamber 21 and has its upper end flanged, as shown at 45, which is clamped against a ring 46 supported by a shoulder 47 formed on the upper end of the bowl 20. The chamber 35 of the expansible member 36 is therefore sealed against communication with the chamber 21 and is only open to the passage 34, chamber 31 and the pipe 13. 7 It is also in communication normally with the low pressure chamber 33 in the pipe 15 and is adapted to be normally filled with oil or lubricant which is carried around by the refrigerant. The lubricant settles past the valve 40 and through the passage 31 enters the chamber 35.

r A spring 50 located within the chamber of the expansible member 36 has one end in engagement with a cap 22 and the other end in engagement with the inner face of the bottom 44 of the expansible member. This spring normally maintains the expansible member extended. A spring 51 has one end in engagement with the outer face of the bottom 44 of the expansible member while the other end of the spring engages adisc 52 seated upon a shoulder 53 formed in the nipple 24. The,upper end of the plug 26 engages the plate 52 and is adapted to regu-- late the tension on the spring 51.

A thermostatic bulb 55 is in communication with the chamber 21 of the bowl 20 by means of a pipe 56. The bulb 55 of the pipe 56 and the chamber 21 contains a medium, usually a gas, which is subject to temperature changes so that when the temperature is sufficien'tly low the gas will be contracted and will not act upon the expansible member 26. On the other hand when the temperature is above a predetermined degree it will act on the expansible member 36 and move the hottom 44 upwardly in connection with the action of the spring 51 for maintaining the valve 40in open position.

The operation of my device is as follows: The high pressure liquid refrigerant enters the valve chamber 31 from the pipe 13, passes the valve seat 41 and through the passage 34 enters the low pressure chamber 33. Theexpansion of the high pressure gas when released into the pipe 15 and the coil 16 cre- CT) ates a pressure in the chamber 33'which is communicated to the oil or lubricant in the chamber 36 of the expansible member 36. When the pressure is sufficiently great to overcome any pressure in the chamber 21 and the spring 51 of the expansible member will be valve 40 to permit-the flow of the refrigerant from the pipe 13 to the pipe 15.

If for some reason the temperature in the bulb 55, which is connected by means of a strap 60 to the pipe 12 at one side of the ex pansion coil 16, is increased sufficiently the pressure exerted by the medium in the bulb 55, the passage 56 and the. valve 21 will cause the expansible member 36 to contract and thereby open the valve 40.

The plug 26 may be adjusted by operating the lock nut 28 in order to-increase or decrease the tension on the spring 51. When the adjustment is satisfactory the lock nut 28 may be screwed up tight upon the outer end of the nipple 24 so that the plug will be retained in position.

I claim: I

1. In a refrigerating system including an expansion coil and a compressor, a-deviee for controlling the flow of the refrigerant from the compressor to the expansion coil comprising a pipe connecting the compressor with the expansion coil, a valve interpolated in the pipe for cutting off the flow of the refrigerant to the expansion coil, an expansible member to the expansion coil, and expansible member in communication with the pipe and containmg 011, a valve stem connecting the valve with the expansible member, pressure in the expansion coil acting on the oil causing expansion .of the expansible member thereby tending to close the valve, a casing embracing the expansible member, a thermostatic bulb in communication with the casing, said casing and bulb containing a medium responsive to temperture changes and acting on the expansible member to cause closing ofthe valve.

3. In a refrigeratingsystem including an expansion coil and a compressor, a device for controlling the flow of the refrigerant from the compressor to the expansion coil com rising a pipe connecting the compressor wit the the expansion coil, a valve interpolated in the pipe for cutting ofl the flow of the re frigerant to the expansion coil, an expansible member in communication with the pipe and containing oil, a valve stem connecting the valve with the expansible member, pressure in the expansion coil acting onothe oil causing expansion of the expansible member thereby tending to close the valve, a casing embracing the expansible member, a thermostatic bulb in communication with the casing, said casing and bulb containing a medium responsive to the temperature changes and acting on the expansible member to cause closing of the valve, said bulb being attached to the outlet side of the expansion coil.

EUGENE H. THREADGILL. 

